1. Field of the Invention
The present invention relates to a solenoid actuated valve device and more particularly to a solenoid actuated valve device for controlling the flow of fluid in proportion to the electric current energizing the solenoid.
2. Description of the Prior Art
A conventional solenoid actuated valve device is comprised of a linear motor of the movable coil type, a valve means and spring means normally biasing the valve means to an inoperative position. The linear motor includes a magnetic core, a non-magnetic bobbin slidably mounted on the core, a solenoid coil wound on the bobbin, permanent magnets mounted adjacent the solenoid coil so that the magnetic flux of each magnet intersects the winding of the solenoid coil at right angles thereto and a magnetic yoke or body forming a magnetic circuit with the core. The valve means in general includes at least one sliding valve member which slides with the bobbin on the core against the biasing force of the spring means in response to an electric current flowing through the solenoid coil. Movement of the valve member proportionally controls the opening and closing of at least one aperture formed in the core between inlet and outlet ports positioned at opposite ends of the body, respectively.
The U.S. Patent to Ohumi, No. 4,294,286 granted on Oct. 13, 1981 and U.S. patent application Ser. No. 156,162 filed on June 3, 1980 in the name of Ohumi et al are examples of such solenoid actuated valve devices.
In such prior solenoid actuated valve devices, the spring means is seated against a radially outwardly extending annular flange of the bobbin. Such annular flange in the device shown in the U.S. Pat. No. 4,294,286 acts as an obstacle to the flow of fluid between the inlet and outlet ports, thereby causing the inaccurate sliding movement of the sliding valve due to the axial thrust force exerted on the annular flange by striking of the fluid flow thereto.
Such inaccurate sliding movement of the sliding valve is avoided in the latter discussed prior art device of Ser. No. 156,162 because the body is provided with axially extending bypass passages in the peripheral wall thereof for decreasing the axial thrust force acting on the annular flange to an extent wherein the sliding valve receives no substantial urging force from the fluid flow. However, the arrangement of bypass passages in the peripheral wall of the body increases the diameter of the body.
Accordingly, it is an object of the present invention to provide a new and improved solenoid actuated valve device which obviates the above-mentioned drawbacks of prior art solenoid actuated valve devices.
More particularly, it is an object of the present invention to provide a new and improved solenoid actuated valve device wherein the axial thrust force acting on the internal components of the device is decreased without increasing the diameter of the body so that no substantial biasing force is exerted by the fluid flow on those internal components.
Additional objects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.